TITLE: GCN CIRCULAR NUMBER: 37578 SUBJECT: EP240919a / GRB 240919A: KAIT optical upper limit DATE: 24/09/20 16:40:23 GMT FROM: Weikang Zheng at UC Berkeley <weikang@berkeley.edu> WeiKang Zheng (UCB), Xuhui Han (NAOC), Pinpin Zhang (NAOC) and Alexei V. Filippenko (UCB) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to EP240919a/GRB 240919A (Liang et al., GCN 37561; Liang et al., GCN Circ. 37563; Rodi et al., GCN 37572; Wang et al., GCN 37574) starting at 03:03 UT, Sep 20th, ~12.7 hours after the trigger. A set of 30x60s images were obtained in the clear (roughly R) filters. Preliminary analysis do not reveal any new optical counterpart candidate within the EP-FXT error circle of the X-ray counterpart (Liang et al., GCN 37561) neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 19.5 mag, and about 20.5 mag in the co-add image. View this GCN Circular online at https://gcn.nasa.gov/circulars/37578. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...